Bio-based acrylate pressure-sensitive adhesive and preparation method thereof

Abstract

The invention discloses a bio-based acrylate pressure-sensitive adhesive and a preparation method thereof. The pressure-sensitive adhesive comprises a terpene derivative monomer, an isosorbide derivative monomer, a cross-linking agent isosorbide derivative, a thermal initiator, a photoinitiator, a solvent and a monomer diluent. According to the preparation method, an isosorbide derivative monomer is introduced into a polymer chain segment in a thermal initiation manner, and meanwhile, another generated isosorbide derivative byproduct is fully utilized as a cross-linking agent to be added so as to form a pressure-sensitive adhesive cross-linked network, and a semi-IPN network is constructed so as to enhance the comprehensive performance of the bio-based pressure-sensitive adhesive. In addition, the concentration of the prepolymer is adjusted through the monomer diluent, and continuous synthesis of the prepolymer is ensured. Finally, the biological raw materials adopted in the method have the potential possibility of replacing fossil raw materials and have the characteristic of being environmentally friendly.

Description

Technical Field

[0001] The invention belongs to the technical field of pressure-sensitive adhesives, and in particular relates to a bio-based acrylate pressure-sensitive adhesive and a preparation method thereof. Background Art

[0002] Pressure-sensitive adhesives are adhesives that quickly adhere to a variety of surfaces with minimal pressure. Their main feature is that the bonding process does not require water, solvents or heat to activate; only pressure is required for effective bonding. Pressure-sensitive adhesives derive their stickiness from their polymer structure, which enables them to flow and fill microscopic irregularities when in contact with the target surface, forming a strong bond. This type of adhesive plays a key role in modern society with a wide range of applications in industries such as label production, healthcare, office automation, electronic equipment assembly, and automotive and construction.

[0003] At present, bio-based acrylate pressure-sensitive adhesives mostly use cross-linking to construct a tight polymer network to improve comprehensive performance. Chinese patent application CN2020111752933.0 discloses a UV-curable bio-based pressure-sensitive adhesive and a preparation method thereof, which is cross-linked by bifunctional 1,6-hexanediol diacrylate. Although the addition of the cross-linking agent forms a network structure, it reduces the bio-based content of the pressure-sensitive adhesive. Patent CN201910929850.2 A high-biobased adhesive and a preparation method and a pressure-sensitive tape, specifically including a UV irradiation method to photoinitiate polymerization of bio-based monomers to prepare a pressure-sensitive adhesive. Patent CN202011172933.0 relates to a UV-curable bio-based pressure-sensitive adhesive, a pressure-sensitive tape and a preparation method thereof, and the pressure-sensitive adhesive is also prepared by UV curing. However, in the process of preparing the prepolymer, the viscosity of the prepolymer needs to be precisely controlled, which causes inconvenience to the continuous production of the product. At the same time, the bio-based hard monomers used are similar to methacrylic acid, isobornyl methacrylate and other monomers commonly used in polymers, and have not broadened the application scope of bio-based monomers for pressure-sensitive adhesives. Summary of the invention

[0004] The invention provides a bio-based acrylate pressure-sensitive adhesive and a preparation method thereof, so as to solve the problems in the prior art.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] A method for preparing a bio-based acrylic pressure-sensitive adhesive, the method uses a thermal initiation method to introduce a terpene derivative monomer and an isosorbide derivative monomer into a polymer segment, and at the same time fully utilizes another isosorbide derivative byproduct generated as a cross-linking agent to form a pressure-sensitive adhesive cross-linking network, and constructs a semi-IPN network to enhance the comprehensive performance of the bio-based pressure-sensitive adhesive. In addition, the concentration of the prepolymer is adjusted by a monomer diluent to ensure continuous synthesis of the prepolymer. Finally, the biological raw materials used in the present invention have the potential to replace fossil raw materials and have environmentally friendly characteristics.

[0008] Terpenes are a large and structurally diverse class of renewable organic compounds. They can be structurally distinguished from other naturally occurring compounds because they are made up of isoprene units. Due to this structural diversity and high functionality, the interest of the chemical and polymer industries in these compounds is growing. They offer a wide range of polymer properties and multifunctional functionalization possibilities. At the same time, it has a long chain structure, which is an important factor that makes the polymer flexible.

[0009] Isosorbide, a carbohydrate that has attracted much attention for its excellent performance in polymer applications, has developed into a commercially available chemical product with the continuous evolution of production technology. It is generated by dehydration reaction of sorbitol as a diol, and its molecular structure includes two active hydroxyl groups, which can be effectively modified as a functional monomer. For example, dimethyl isosorbide is often used as a solvent in cosmetics, while isosorbide esters can act as surfactants. In addition, given that the strong backbone structure of isosorbide is composed of two furan units, its overall structure has a high degree of elasticity, making isosorbide a popular monomer for synthesizing high-performance bio-based polymers. The modified isosorbide derivative monomer is introduced into the acrylate segment, which can significantly optimize the mechanical properties of this bio-based pressure-sensitive adhesive. At the same time, the cross-linking agent isosorbide derivative can construct a cross-linked network, which enables this bio-based pressure-sensitive adhesive to form a higher shear strength.

[0010] A bio-based acrylate pressure-sensitive adhesive, comprising, by weight: 90-100 parts of a terpene derivative monomer, 0-16 parts of an isosorbide derivative monomer, 0-0.3 parts of a thermal initiator, 0.5-1 parts of a photoinitiator, 0-0.2 parts of an isosorbide derivative cross-linking agent, 200-250 parts of a solvent, and 0-50 parts of a monomer diluent;

[0011] The terpene derivative monomer is prepared by modifying terpenes; the isosorbide derivative monomer and the cross-linking agent isosorbide derivative are prepared by modifying isosorbide.

[0012] Preferably, a bio-based acrylate pressure-sensitive adhesive comprises, in parts by weight, 90 to 100 parts by weight of a terpene derivative monomer, 0 to 16 parts by weight of an isosorbide derivative monomer, 0.5 parts by weight of a photoinitiator, 0 to 0.2 parts by weight of a cross-linking agent isosorbide, 220 to 230 parts by weight of a solvent, and 50 parts of a monomer diluent.

[0013] Further, the terpene derivative monomer is tetrahydrogeraniol acrylate;

[0014] The thermal initiator is at least one of organic peroxides, inorganic peroxides, azos, and redox initiators. Further, the thermal initiator is azobisisobutyronitrile and azobisisoheptanonitrile in the azo group. Preferably, the thermal initiator is azobisisoheptanonitrile.

[0015] The solvent is at least one of toluene, acetone and ethyl acetate, preferably, the solvent is ethyl acetate;

[0016] The photoinitiator is 2-methyl-1-(4-methylthiophenyl)-2-morpholinyl-1-propanone;

[0017] The monomer diluent is tetrahydrogeraniol acrylate.

[0018] Further, the preparation method of the tetrahydrogeraniol acrylate is as follows:

[0019] Step 101, dissolving tetrahydrogeraniol in a mixture of triethylamine and anhydrous dichloromethane, then dropping acryloyl chloride therein at 0° C., stirring the mixture to obtain a terpene derivative mixture;

[0020] Step 102: After the reaction is completed, the reaction is quenched with distilled water, extracted with anhydrous dichloromethane, the organic layers are combined, washed with a saturated saline solution, dried over anhydrous sodium sulfate, filtered and distilled under reduced pressure to obtain a crude product, and the crude product is separated by a chromatographic column to obtain pure monomer tetrahydrogeraniol acrylate.

[0021] Furthermore, in the step 101, the amount of tetrahydrogeraniol is 0.8-1.2 times the amount of acryloyl chloride, preferably 1.2 times; the amount of triethylamine is 1-1.5 times the amount of tetrahydrogeraniol, preferably 1.5 times; the amount of anhydrous dichloromethane is 10-15 times the amount of tetrahydrogeraniol, preferably 10 times;

[0022] In the step 101, the rate of adding acryloyl chloride is 0.3 mL / h to 0.6 mL / h, preferably 0.5 mL / h; the reaction time is 10 h to 12 h, preferably 12 h; and the reaction temperature is 20° C. to 25° C., preferably 25° C.

[0023] Furthermore, the preparation method of the isosorbide derivative monomer and the cross-linking agent isosorbide derivative is as follows:

[0024] Step 201, dissolving isosorbide in a mixture of triethylamine, anhydrous tetrahydrofuran and anhydrous dichloromethane, then adding acryloyl chloride thereto at 0°C, and stirring the mixture to obtain an isosorbide derivative mixture;

[0025] Step 202: After the reaction is completed, the reaction is quenched with distilled water, extracted with anhydrous dichloromethane, the organic layers are combined, washed with a saturated saline solution, dried over anhydrous sodium sulfate, filtered and distilled under reduced pressure to obtain a crude product, and the crude product is separated by a chromatographic column to obtain an isosorbide derivative monomer and a cross-linking agent isosorbide derivative.

[0026] Further, in the step 201, the amount of isosorbide is 1 to 3 times the amount of acryloyl chloride, preferably 2 times; the amount of triethylamine is 1 to 2 times the amount of isosorbide, preferably 1.5 times; the amount of anhydrous dichloromethane is 10 to 15 times the amount of isosorbide, preferably 10 times; the amount of anhydrous tetrahydrofuran is 1 to 3 times the amount of isosorbide, preferably 2 times;

[0027] In step 201, the rate of dropping acryloyl chloride is 0.3 mL / h to 0.6 mL / h, preferably 0.5 mL / h; the reaction time is 20 h to 30 h, preferably 24 h; and the reaction temperature is 20° C. to 25° C., preferably 25° C.

[0028] A method for preparing a bio-based acrylate pressure-sensitive adhesive comprises the following steps:

[0029] Step 301: adding the synthesized tetrahydrogeraniol acrylate and the synthesized isosorbide derivative monomer into a solvent according to a ratio, and adding a thermal initiator, and heating the mixture to react to obtain a prepolymer solution;

[0030] Step 302, removing the solvent of the prepolymer solution by distillation under reduced pressure, adding a monomer diluent, a photoinitiator and a synthesized cross-linking agent isosorbide derivative, and mixing them thoroughly to obtain an uncured adhesive solution;

[0031] Step 303: coating the adhesive solution and curing it by light to obtain a bio-based acrylate pressure-sensitive adhesive.

[0032] Further, in step 301, the reaction temperature is 55 to 65°C, preferably 65°C, and the reaction time is 10 to 20 hours, preferably 12 hours;

[0033] In step 302, the amount of the monomer diluent added is 30% to 60% of the mass of the prepolymer synthesized in step 301, preferably 50%; the amount of the photoinitiator added is 1% to 2% of the mass of the added diluent, preferably 1%; the amount of the cross-linking agent isosorbide derivative added is 0% to 3% of the mass of the diluent;

[0034] In step 303, the coating thickness of the glue is 30 μm to 100 μm, preferably 65 μm; the curing parameter of the glue is 1500 mJ / cm 2 ~2000mJ / cm 2 、6mW / cm 2 ~8mW / cm 2 , 25℃~30℃, preferably 2000mJ / cm 2 , 8mW / cm 2 , 25°C; the substrate coated with the adhesive is polyethylene terephthalate.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] 1. The present invention introduces terpene derivative monomers into the polymer chain segment, further broadening the application of terpenes in the field of pressure-sensitive adhesives.

[0037] 2. The invention introduces isosorbide derivative monomers into the polymer chain segments, which helps to improve the cohesion and adhesion of the pressure-sensitive adhesive. The cross-linking agent isosorbide derivative is generated simultaneously during the synthesis of the isosorbide derivative monomers, thereby fully utilizing the synthesized product.

[0038] 3. The present invention introduces the cross-linking agent isosorbide derivative to construct a semi-IPN cross-linked network structure, which helps to improve the comprehensive performance of the pressure-sensitive adhesive.

[0039] 4. The present invention adopts light curing technology in the curing stage, presenting an extremely high curing rate, greatly reducing production costs, and significantly improving output efficiency. In addition, light curing also meets the needs of modern society for sustainable development and green production.

[0040] 5. The present invention adopts the method of adding a monomer diluent to adjust the viscosity of the prepolymer, which can ensure the continuity of the prepolymer synthesis.

[0041] 6. The biological raw materials used in the present invention have the potential to replace fossil raw materials and are environmentally friendly. DETAILED DESCRIPTION

[0042] The present invention will be further described below in conjunction with the embodiments.

[0043] A bio-based acrylate pressure-sensitive adhesive, comprising, by weight: 90-100 parts of a terpene derivative monomer, 0-16 parts of an isosorbide derivative monomer, 0-0.3 parts of a thermal initiator, 0.5-1 parts of a photoinitiator, 0-0.2 parts of an isosorbide derivative cross-linking agent, 200-250 parts of a solvent, and 0-50 parts of a monomer diluent;

[0044] Wherein, the terpene derivative monomer is prepared by modifying terpenes; the isosorbide derivative monomer and the cross-linking agent isosorbide derivative are prepared by modifying isosorbide;

[0045] As a preferred embodiment, a bio-based acrylate pressure-sensitive adhesive includes, in parts by weight, 90 to 100 parts by weight of a terpene derivative monomer, 0 to 16 parts by weight of an isosorbide derivative monomer, 0.5 parts by weight of a photoinitiator, 0 to 0.2 parts by weight of a cross-linking agent isosorbide, 220 to 230 parts by weight of a solvent, and 50 parts of a monomer diluent.

[0046] As a preferred embodiment, the terpene derivative monomer is tetrahydrogeraniol acrylate; the thermal initiator is at least one of organic peroxides, inorganic peroxides, azos, and redox types, and further the thermal initiator is azobisisobutyronitrile and azobisisoheptanenitrile in the azo type, preferably the thermal initiator is azobisisoheptanenitrile; the solvent is at least one of toluene, acetone, and ethyl acetate, preferably the solvent is ethyl acetate; the photoinitiator is 2-methyl-1-(4-methylthiophenyl)-2-morpholinyl-1-propanone; and the monomer diluent is tetrahydrogeraniol acrylate.

[0047] As a preferred embodiment, the preparation method of tetrahydrogeraniol acrylate is as follows:

[0048] Step 101, dissolving tetrahydrogeraniol in a mixture of triethylamine and anhydrous dichloromethane, then dropping acryloyl chloride therein at 0° C., stirring the mixture to obtain a terpene derivative mixture;

[0049] Step 102: After the reaction is completed, the reaction is quenched with distilled water, extracted with anhydrous dichloromethane, the organic layers are combined, washed with a saturated saline solution, dried over anhydrous sodium sulfate, filtered and distilled under reduced pressure to obtain a crude product, and the crude product is separated by a chromatographic column to obtain pure monomer tetrahydrogeraniol acrylate.

[0050] As a preferred embodiment, in step 101, the amount of tetrahydrogeraniol is 0.8-1.2 times the amount of acryloyl chloride, preferably 1.2 times; the amount of triethylamine is 1-1.5 times the amount of tetrahydrogeraniol, preferably 1.5 times; the amount of anhydrous dichloromethane is 10-15 times the amount of tetrahydrogeraniol, preferably 10 times;

[0051] As a preferred embodiment, in step 101, the rate of adding acryloyl chloride is 0.3 mL / h to 0.6 mL / h, preferably 0.5 mL / h; the reaction time is 10 h to 12 h, preferably 12 h; and the reaction temperature is 20° C. to 25° C., preferably 25° C.

[0052] As a preferred embodiment, the preparation method of the isosorbide derivative monomer and the cross-linking agent isosorbide derivative is as follows:

[0053] Step 201, dissolving isosorbide in a mixture of triethylamine, anhydrous tetrahydrofuran and anhydrous dichloromethane, then slowly adding acryloyl chloride thereto at 0°C, stirring the mixture to obtain an isosorbide derivative mixture;

[0054] Step 202: After the reaction is completed, the reaction is quenched with distilled water, extracted with anhydrous dichloromethane, the organic layers are combined, washed with a saturated saline solution, dried over anhydrous sodium sulfate, filtered and distilled under reduced pressure to obtain a crude product, and the crude product is separated by a chromatographic column to obtain an isosorbide derivative monomer and a cross-linking agent isosorbide derivative.

[0055] As a preferred embodiment, in step 201, the amount of isosorbide is 1 to 3 times, preferably 2 times, the amount of acryloyl chloride; the amount of triethylamine is 1 to 2 times, preferably 1.5 times, the amount of anhydrous dichloromethane is 10 to 15 times, preferably 10 times, the amount of isosorbide; the amount of anhydrous tetrahydrofuran is 1 to 3 times, preferably 2 times, the amount of isosorbide;

[0056] As a preferred embodiment, in step 201, the rate of adding acryloyl chloride is 0.3 mL / h to 0.6 mL / h, preferably 0.5 mL / h; the reaction time is 20 h to 30 h, preferably 24 h; and the reaction temperature is 20° C. to 25° C., preferably 25° C.

[0057] A method for preparing a bio-based acrylate pressure-sensitive adhesive comprises the following steps:

[0058] Step 301: adding the synthesized tetrahydrogeraniol acrylate and the synthesized isosorbide derivative monomer into a solvent according to a ratio, and adding a thermal initiator, and heating the mixture to react to obtain a prepolymer solution;

[0059] Step 302, removing the solvent of the prepolymer solution by distillation under reduced pressure, adding a monomer diluent, a photoinitiator and a synthesized cross-linking agent isosorbide derivative, and mixing them thoroughly to obtain an uncured adhesive solution;

[0060] Step 303: coating the adhesive solution and curing it by light to obtain a bio-based acrylate pressure-sensitive adhesive.

[0061] As a preferred embodiment, in step 301, the reaction temperature is 55 to 65° C., preferably 65° C., and the reaction time is 10 to 20 hours, preferably 12 hours;

[0062] In step 302, the amount of the monomer diluent added is 30% to 60% of the mass of the prepolymer synthesized in step 301, preferably 50%; the amount of the photoinitiator added is 1% to 2% of the mass of the added diluent, preferably 1%; the amount of the cross-linking agent isosorbide derivative added is 0% to 3% of the mass of the diluent;

[0063] In step 303, the coating thickness of the glue is 30 μm to 100 μm, preferably 65 μm; the curing parameter of the glue is 1500 mJ / cm 2 ~2000mJ / cm 2 、6mW / cm 2 ~8mW / cm 2 , 25℃~30℃, preferably 2000mJ / cm 2 , 8mW / cm 2 , 25°C; the substrate coated with the adhesive is polyethylene terephthalate.

[0064] In the following examples, only the best options are presented for comparison of test results for various reaction parameters.

[0065] Embodiment 1:

[0066] (1) 15 g of tetrahydrogeraniol acrylate was added to 28.2 g of ethyl acetate, and 21.9 mg of azobisisoheptanenitrile was added, and the gas in the bottle was removed by a vacuum pump, followed by purging with high-purity nitrogen, and this operation was repeated three times. The reaction was continued at 65 degrees Celsius for 12 hours to obtain a prepolymer solution.

[0067] (2) After the prepolymer solution is distilled under reduced pressure to remove ethyl acetate, 15 g of the prepolymer glue solution is weighed, and 7.5 g of tetrahydrogeraniol acrylate and 0.16 g of photoinitiator 2-methyl-1-(4-methylthiophenyl)-2-morpholinyl-1-propanone are added thereto to obtain an uncured bio-based acrylic pressure-sensitive adhesive solution.

[0068] (3) The above adhesive solution was coated with a coating machine at a thickness of 65 μm, and cured in a UV curing machine to obtain a bio-based acrylate pressure-sensitive adhesive. The curing parameters were recorded using a UV energy meter. The results are shown in Table 1.

[0069] Embodiment 2:

[0070] (1) 15 g of tetrahydrogeraniol acrylate was added to 28.2 g of ethyl acetate, and 21.9 mg of azobisisoheptanenitrile was added. The gas in the bottle was removed by a vacuum pump, and then purged with high-purity nitrogen. This operation was repeated three times. The reaction was continued at 65° C. for 12 hours to obtain a prepolymer solution.

[0071] (2) After the prepolymer solution is distilled under reduced pressure to remove ethyl acetate, 15 g of the prepolymer glue solution is weighed, 7.5 g of tetrahydrogeraniol acrylate, 0.16 g of a photoinitiator 2-methyl-1-(4-methylthiophenyl)-2-morpholinyl-1-propanone and 35 mg of a cross-linking agent isosorbide derivative are added thereto to obtain an uncured bio-based acrylic pressure-sensitive adhesive solution.

[0072] (3) The above adhesive solution was coated with a coating machine at a thickness of 65 μm, and cured in a UV curing machine to obtain a bio-based acrylate pressure-sensitive adhesive. The curing parameters were recorded using a UV energy meter. The results are shown in Table 1.

[0073] Embodiment 3:

[0074] (1) 15 g of tetrahydrogeraniol acrylate was added to 28.2 g of ethyl acetate, and 21.9 mg of azobisisoheptanenitrile was added. The gas in the bottle was removed by a vacuum pump, and then purged with high-purity nitrogen. This operation was repeated three times. The reaction was continued at 65° C. for 12 hours to obtain a prepolymer solution.

[0075] (2) After the prepolymer solution is distilled under reduced pressure to remove ethyl acetate, 15 g of the prepolymer glue solution is weighed, 7.5 g of tetrahydrogeraniol acrylate, 0.16 g of a photoinitiator 2-methyl-1-(4-methylthiophenyl)-2-morpholinyl-1-propanone and 105 mg of a cross-linking agent isosorbide derivative are added thereto to obtain an uncured bio-based acrylic pressure-sensitive adhesive solution.

[0076] (3) The above adhesive solution was coated with a coating machine at a thickness of 65 μm, and cured in a UV curing machine to obtain a bio-based acrylate pressure-sensitive adhesive. The curing parameters were recorded using a UV energy meter. The results are shown in Table 1.

[0077] Embodiment 4:

[0078] (1) 15 g of tetrahydrogeraniol acrylate and 0.15 g of isosorbide derivative monomer were added to 28.2 g of ethyl acetate, and 21.9 mg of azobisisoheptanenitrile was added. The gas in the bottle was removed by a vacuum pump, and then purged with high-purity nitrogen. This operation was repeated three times. The reaction was continued at 65° C. for 12 hours to obtain a prepolymer solution.

[0079] (2) After the prepolymer solution is distilled under reduced pressure to remove ethyl acetate, 15 g of the prepolymer glue solution is weighed, and 7.5 g of tetrahydrogeraniol acrylate and 0.16 g of photoinitiator 2-methyl-1-(4-methylthiophenyl)-2-morpholinyl-1-propanone are added thereto to obtain an uncured bio-based acrylic pressure-sensitive adhesive solution.

[0080] (3) The above adhesive solution was coated with a coating machine at a thickness of 65 μm, and cured in a UV curing machine to obtain a bio-based acrylate pressure-sensitive adhesive. The curing parameters were recorded using a UV energy meter. The results are shown in Table 1.

[0081] Embodiment 5:

[0082] (1) 15 g of tetrahydrogeraniol acrylate and 0.15 g of isosorbide derivative monomer were added to 28.2 g of ethyl acetate, and 21.9 mg of azobisisoheptanenitrile was added. The gas in the bottle was removed by a vacuum pump, and then purged with high-purity nitrogen. This operation was repeated three times. The reaction was continued at 65° C. for 12 hours to obtain a prepolymer solution.

[0083] (2) After the prepolymer solution is distilled under reduced pressure to remove ethyl acetate, 15 g of the prepolymer glue solution is weighed, 7.5 g of tetrahydrogeraniol acrylate, 0.16 g of a photoinitiator 2-methyl-1-(4-methylthiophenyl)-2-morpholinyl-1-propanone and 35 mg of a cross-linking agent isosorbide derivative are added thereto to obtain an uncured bio-based acrylic pressure-sensitive adhesive solution.

[0084] (3) The above adhesive solution was coated with a coating machine at a thickness of 65 μm, and cured in a UV curing machine to obtain a bio-based acrylate pressure-sensitive adhesive. The curing parameters were recorded using a UV energy meter. The results are shown in Table 1.

[0085] Embodiment 6:

[0086] (1) 15 g of tetrahydrogeraniol acrylate and 0.15 g of isosorbide derivative monomer were added to 28.2 g of ethyl acetate, and 21.9 mg of azobisisoheptanenitrile was added. The gas in the bottle was removed by a vacuum pump, and then purged with high-purity nitrogen. This operation was repeated three times. The reaction was continued at 65° C. for 12 hours to obtain a prepolymer solution.

[0087] (2) After the prepolymer solution is distilled under reduced pressure to remove ethyl acetate, 15 g of the prepolymer glue solution is weighed, 7.5 g of tetrahydrogeraniol acrylate, 0.16 g of a photoinitiator 2-methyl-1-(4-methylthiophenyl)-2-morpholinyl-1-propanone and 105 mg of a cross-linking agent isosorbide derivative are added thereto to obtain an uncured bio-based acrylic pressure-sensitive adhesive solution.

[0088] (3) The above adhesive solution was coated with a coating machine at a thickness of 65 μm, and cured in a UV curing machine to obtain a bio-based acrylate pressure-sensitive adhesive. The curing parameters were recorded using a UV energy meter. The results are shown in Table 1.

[0089] Embodiment 7:

[0090] (1) 15 g of tetrahydrogeraniol acrylate and 0.5 g of isosorbide derivative monomer were added to 28.2 g of ethyl acetate, and 21.9 mg of azobisisoheptanenitrile was added. The gas in the bottle was removed by a vacuum pump, and then purged with high-purity nitrogen. This operation was repeated three times. The reaction was continued at 65° C. for 12 hours to obtain a prepolymer solution.

[0091] (2) After the prepolymer solution is distilled under reduced pressure to remove ethyl acetate, 15 g of the prepolymer glue solution is weighed, and 7.5 g of tetrahydrogeraniol acrylate and 0.16 g of photoinitiator 2-methyl-1-(4-methylthiophenyl)-2-morpholinyl-1-propanone are added thereto to obtain an uncured bio-based acrylic pressure-sensitive adhesive solution.

[0092] (3) The above adhesive solution was coated with a coating machine at a thickness of 65 μm, and cured in a UV curing machine to obtain a bio-based acrylate pressure-sensitive adhesive. The curing parameters were recorded using a UV energy meter. The results are shown in Table 1.

[0093] Embodiment 8:

[0094] (1) 15 g of tetrahydrogeraniol acrylate and 0.5 g of isosorbide derivative monomer were added to 28.2 g of ethyl acetate, and 21.9 mg of azobisisoheptanenitrile was added. The gas in the bottle was removed by a vacuum pump, and then purged with high-purity nitrogen. This operation was repeated three times. The reaction was continued at 65° C. for 12 hours to obtain a prepolymer solution.

[0095] (2) After the prepolymer solution is distilled under reduced pressure to remove ethyl acetate, 15 g of the prepolymer glue solution is weighed, 7.5 g of tetrahydrogeraniol acrylate, 0.16 g of a photoinitiator 2-methyl-1-(4-methylthiophenyl)-2-morpholinyl-1-propanone and 35 mg of a cross-linking agent isosorbide derivative are added thereto to obtain an uncured bio-based acrylic pressure-sensitive adhesive solution.

[0096] (3) The above adhesive solution was coated with a coating machine at a thickness of 65 μm, and cured in a UV curing machine to obtain a bio-based acrylate pressure-sensitive adhesive. The curing parameters were recorded using a UV energy meter. The results are shown in Table 1.

[0097] Embodiment 9:

[0098] (1) 15 g of tetrahydrogeraniol acrylate and 0.5 g of isosorbide derivative monomer were added to 28.2 g of ethyl acetate, and 21.9 mg of azobisisoheptanenitrile was added. The gas in the bottle was removed by a vacuum pump, and then purged with high-purity nitrogen. This operation was repeated three times. The reaction was continued at 65° C. for 12 hours to obtain a prepolymer solution.

[0099] (2) After the prepolymer solution is distilled under reduced pressure to remove ethyl acetate, 15 g of the prepolymer glue solution is weighed, 7.5 g of tetrahydrogeraniol acrylate, 0.16 g of a photoinitiator 2-methyl-1-(4-methylthiophenyl)-2-morpholinyl-1-propanone and 105 mg of a cross-linking agent isosorbide derivative are added thereto to obtain an uncured bio-based acrylic pressure-sensitive adhesive solution.

[0100] (3) The above adhesive solution was coated with a coating machine at a thickness of 65 μm, and cured in a UV curing machine to obtain a bio-based acrylate pressure-sensitive adhesive. The curing parameters were recorded using a UV energy meter. The results are shown in Table 1.

[0101] Embodiment 10:

[0102] (1) 15 g of tetrahydrogeraniol acrylate and 0.75 g of isosorbide derivative monomer were added to 28.2 g of ethyl acetate, and 21.9 mg of azobisisoheptanenitrile was added. The gas in the bottle was removed by a vacuum pump, and then purged with high-purity nitrogen. This operation was repeated three times. The reaction was continued at 65° C. for 12 hours to obtain a prepolymer solution.

[0103] (2) After the prepolymer solution is distilled under reduced pressure to remove ethyl acetate, 15 g of the prepolymer glue solution is weighed, and 7.5 g of tetrahydrogeraniol acrylate and 0.16 g of photoinitiator 2-methyl-1-(4-methylthiophenyl)-2-morpholinyl-1-propanone are added thereto to obtain an uncured bio-based acrylic pressure-sensitive adhesive solution.

[0104] (3) The above adhesive solution was coated with a coating machine at a thickness of 65 μm, and cured in a UV curing machine to obtain a bio-based acrylate pressure-sensitive adhesive. The curing parameters were recorded using a UV energy meter. The results are shown in Table 1.

[0105] Embodiment 11:

[0106] (1) 15 g of tetrahydrogeraniol acrylate and 0.75 g of isosorbide derivative monomer were added to 28.2 g of ethyl acetate, and 21.9 mg of azobisisoheptanenitrile was added. The gas in the bottle was removed by a vacuum pump, and then purged with high-purity nitrogen. This operation was repeated three times. The reaction was continued at 65° C. for 12 hours to obtain a prepolymer solution.

[0107] (2) After the prepolymer solution is distilled under reduced pressure to remove ethyl acetate, 15 g of the prepolymer glue solution is weighed, 7.5 g of tetrahydrogeraniol acrylate, 0.16 g of a photoinitiator 2-methyl-1-(4-methylthiophenyl)-2-morpholinyl-1-propanone and 35 mg of a cross-linking agent isosorbide derivative are added thereto to obtain an uncured bio-based acrylic pressure-sensitive adhesive solution.

[0108] (3) The above adhesive solution was coated with a coating machine at a thickness of 65 μm, and cured in a UV curing machine to obtain a bio-based acrylate pressure-sensitive adhesive. The curing parameters were recorded using a UV energy meter. The results are shown in Table 1.

[0109] Embodiment 12:

[0110] (1) 15 g of tetrahydrogeraniol acrylate and 0.75 g of isosorbide derivative monomer were added to 28.2 g of ethyl acetate, and 21.9 mg of azobisisoheptanenitrile was added. The gas in the bottle was removed by a vacuum pump, and then purged with high-purity nitrogen. This operation was repeated three times. The reaction was continued at 65° C. for 12 hours to obtain a prepolymer solution.

[0111] (2) After the prepolymer solution is distilled under reduced pressure to remove ethyl acetate, 15 g of the prepolymer glue solution is weighed, 7.5 g of tetrahydrogeraniol acrylate, 0.16 g of a photoinitiator 2-methyl-1-(4-methylthiophenyl)-2-morpholinyl-1-propanone and 105 mg of a cross-linking agent isosorbide derivative are added thereto to obtain an uncured bio-based acrylic pressure-sensitive adhesive solution.

[0112] (3) The above adhesive solution was coated with a coating machine at a thickness of 65 μm, and cured in a UV curing machine to obtain a bio-based acrylate pressure-sensitive adhesive. The curing parameters were recorded using a UV energy meter. The results are shown in Table 1.

[0113] Table 1 Effects of different contents of terpene derivative monomers, different contents of isosorbide derivative monomers and different contents of crosslinking agent isosorbide derivatives in prepolymer on the performance test of pressure-sensitive adhesive

[0114]

[0115] The gel fraction in Table 1 was tested as follows:

[0116] Take about 0.1g of the pressure-sensitive adhesive sample from different embodiments, dissolve it in 25mL of ethyl acetate, and let it stand for 24 hours. Then, filter it with a 200-mesh copper mesh to obtain the remaining residue. The residue is placed in a well-ventilated environment until the quality becomes stable;

[0117] The gel fraction in Table 1 was calculated according to the following formula:

[0118] Gel(%)=W b / W n ×100%

[0119] Where: Gel-gel fraction; W b W is the residual mass of pressure-sensitive adhesive (g); n To weigh the pressure-sensitive adhesive mass (g)

[0120] Peel force test: According to GB / T 2792-2014 standard, the peel force of pressure-sensitive adhesive is measured;

[0121] Initial adhesion test: According to GB / T 4852-2002 standard, the initial adhesion of pressure-sensitive adhesive is measured;

[0122] Adhesion test: According to GB / T 4851-2014 standard, the adhesion of pressure-sensitive adhesive is measured;

[0123] The results show that although the example samples (Examples 1-3) without the addition of isosorbide derivative monomers have relatively good peeling force, the holding force is poor. The comprehensive mechanical properties of the example samples (Examples 4-9) with the addition of isosorbide derivative monomers have been significantly improved. With the introduction of an appropriate amount of cross-linking agent, the mechanical properties of the pressure-sensitive adhesive are also improved. It can be seen that these two isosorbide derivatives play a vital role in the bio-based pressure-sensitive adhesive of this system.

[0124] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A bio-based acrylate pressure-sensitive adhesive, characterized in that: In parts by weight: 90-100 parts of terpene derivative monomer, 0-16 parts of isosorbide derivative monomer, Thermal initiator 0-0.3 parts, Photoinitiator 0.5-1 part, Cross-linking agent isosorbide derivative 0-0.2 parts, 200-250 parts of solvent, 0-50 parts of monomer diluent; The terpene derivative monomer is prepared by modifying terpenes; the isosorbide derivative monomer and the cross-linking agent isosorbide derivative are prepared by modifying isosorbide.

2. The bio-based acrylate pressure-sensitive adhesive according to claim 1, characterized in that: The terpene derivative monomer is tetrahydrogeraniol acrylate; The thermal initiator is azobisisoheptanonitrile; The solvent is at least one of toluene, acetone and ethyl acetate; The photoinitiator is 2-methyl-1-(4-methylthiophenyl)-2-morpholinyl-1-propanone; The monomer diluent is tetrahydrogeraniol acrylate.

3. The bio-based acrylate pressure-sensitive adhesive according to claim 2, characterized in that: The preparation method of the tetrahydrogeraniol acrylate is as follows: Step 101, dissolving tetrahydrogeraniol in a mixture of triethylamine and anhydrous dichloromethane, and then dropping acryloyl chloride therein at 0°C, stirring the mixture to obtain a terpene derivative mixture; Step 102: After the reaction is completed, the reaction is quenched with distilled water, extracted with anhydrous dichloromethane, the organic layers are combined, washed with a saturated saline solution, dried over anhydrous sodium sulfate, filtered and distilled under reduced pressure to obtain a crude product, and the crude product is separated by a chromatographic column to obtain pure monomer tetrahydrogeraniol acrylate.

4. The bio-based acrylate pressure-sensitive adhesive according to claim 3, characterized in that: In the step 101, the amount of tetrahydrogeraniol used is 0.8-1.2 times the amount of acryloyl chloride used; The amount of triethylamine used is 1 to 1.5 times the amount of tetrahydrogeraniol used; The amount of anhydrous dichloromethane used is 10 to 15 times that of tetrahydrogeraniol; In the step 101, the rate of adding acryloyl chloride is 0.3 mL / h to 0.6 mL / h; In step 101, the reaction time is 10 h to 12 h; In the step 101, the reaction temperature is 20°C to 25°C.

5. The bio-based acrylate pressure-sensitive adhesive according to claim 1, characterized in that: The preparation methods of the isosorbide derivative monomer and the cross-linking agent isosorbide derivative are as follows: Step 201, dissolving isosorbide in a mixture of triethylamine, anhydrous tetrahydrofuran and anhydrous dichloromethane, then adding acryloyl chloride thereto at 0°C, and stirring the mixture to obtain an isosorbide derivative mixture; Step 202: After the reaction is completed, the reaction is quenched with distilled water, extracted with anhydrous dichloromethane, the organic layers are combined, washed with a saturated saline solution, dried over anhydrous sodium sulfate, filtered and distilled under reduced pressure to obtain a crude product, and the crude product is separated by a chromatographic column to obtain an isosorbide derivative monomer and a cross-linking agent isosorbide derivative.

6. The bio-based acrylate pressure-sensitive adhesive according to claim 5, characterized in that: In step 201, the amount of isosorbide used is 1 to 3 times the amount of acryloyl chloride used; In the step 201, the amount of triethylamine used is 1 to 2 times the amount of isosorbide used; In step 201, the amount of anhydrous dichloromethane used is 10 to 15 times the amount of isosorbide used; In the step 201, the amount of anhydrous tetrahydrofuran used is 1 to 3 times the amount of isosorbide used; In the step 201, the rate of adding acryloyl chloride is 0.3 mL / h to 0.6 mL / h; In the step 201, the reaction time is 20h to 30h; In step 201, the reaction temperature is 20°C to 25°C.

7. The method for preparing the bio-based acrylate pressure-sensitive adhesive according to any one of claims 1 to 6, characterized in that: The following steps are involved: Step 301: adding the synthesized tetrahydrogeraniol acrylate and the synthesized isosorbide derivative monomer into a solvent according to a ratio, and adding a thermal initiator, and heating the mixture to react to obtain a prepolymer solution; Step 302, removing the solvent of the prepolymer solution by distillation under reduced pressure, adding a monomer diluent, a photoinitiator and a synthesized cross-linking agent isosorbide derivative, and mixing them thoroughly to obtain an uncured adhesive solution; Step 303: coating the adhesive solution and curing it by light to obtain a bio-based acrylate pressure-sensitive adhesive.

8. The method for preparing the bio-based acrylate pressure-sensitive adhesive according to claim 7, characterized in that: In step 301, the reaction temperature is 55-65° C., and the reaction time is 10-20 hours.

9. The method for preparing the isosorbide bio-based acrylate pressure-sensitive adhesive according to claim 7, characterized in that: In step 302, the amount of the added monomer diluent is 30% to 60% of the mass of the prepolymer synthesized in step 301; In step 302, the amount of photoinitiator added is 1% to 2% of the mass of the added diluent; In step 302, the amount of the added cross-linking agent isosorbide derivative is 0% to 3% of the mass of the diluent.

10. The method for preparing the isosorbide bio-based acrylate pressure-sensitive adhesive according to claim 7, characterized in that: In step 303, the coating thickness of the glue is 30 μm to 100 μm; In step 303, the curing parameter of the glue is 1500mJ / cm 2 ~2000mJ / cm 2 、6mW / cm 2 ~8mW / cm 2 , 25℃~30℃; In step 303, the substrate is coated with the adhesive to obtain polyethylene terephthalate.

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